/*-------------------------------------------------------------------------
 *
 * pgtime.h
 *      PostgreSQL internal timezone library
 *
 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *      src/include/pgtime.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef _PGTIME_H
#define _PGTIME_H


/*
 * The API of this library is generally similar to the corresponding
 * C library functions, except that we use pg_time_t which (we hope) is
 * 64 bits wide, and which is most definitely signed not unsigned.
 */

typedef int64 pg_time_t;

struct pg_tm
{
    int            tm_sec;
    int            tm_min;
    int            tm_hour;
    int            tm_mday;
    int            tm_mon;            /* origin 1, not 0! */
    int            tm_year;        /* relative to 1900 */
    int            tm_wday;
    int            tm_yday;
    int            tm_isdst;
    long int    tm_gmtoff;
    const char *tm_zone;
};

typedef struct pg_tz pg_tz;
typedef struct pg_tzenum pg_tzenum;

/* Maximum length of a timezone name (not including trailing null) */
#define TZ_STRLEN_MAX 255

/* these functions are in localtime.c */

extern struct pg_tm *pg_localtime(const pg_time_t *timep, const pg_tz *tz);
extern struct pg_tm *pg_gmtime(const pg_time_t *timep);
extern int pg_next_dst_boundary(const pg_time_t *timep,
                     long int *before_gmtoff,
                     int *before_isdst,
                     pg_time_t *boundary,
                     long int *after_gmtoff,
                     int *after_isdst,
                     const pg_tz *tz);
extern bool pg_interpret_timezone_abbrev(const char *abbrev,
                             const pg_time_t *timep,
                             long int *gmtoff,
                             int *isdst,
                             const pg_tz *tz);
extern bool pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff);
extern const char *pg_get_timezone_name(pg_tz *tz);
extern bool pg_tz_acceptable(pg_tz *tz);

/* these functions are in strftime.c */

extern size_t pg_strftime(char *s, size_t max, const char *format,
            const struct pg_tm *tm);

/* these functions and variables are in pgtz.c */

extern pg_tz *session_timezone;
extern pg_tz *log_timezone;

extern void pg_timezone_initialize(void);
extern pg_tz *pg_tzset(const char *tzname);
extern pg_tz *pg_tzset_offset(long gmtoffset);

extern pg_tzenum *pg_tzenumerate_start(void);
extern pg_tz *pg_tzenumerate_next(pg_tzenum *dir);
extern void pg_tzenumerate_end(pg_tzenum *dir);

#endif                            /* _PGTIME_H */
